1. Field of the Invention
The present invention relates to methods of forming conference channels by utilizing an electronic private branch exchange and conference telephone (call) systems embodying the conference-channel forming methods and, more particularly, to a conference-channel forming method based on a private branch exchange and a conference telephone system embodying the method in which, even when conference speeches are carried out among a relatively large number of conference participators, a conference convoker can sufficiently hold the command of the conference speeches and can expedite the proceedings without losing his or her initiative.
2. Description of the prior Art
When it is desired to have a telephone conference (speeches among three or more parties) through a conference telephone system based on a private branch exchange, there has been so far employed such a method that a plurality of operators as participators of the conference talk with each other through their extension telephones and an operator playing a role of a chairman (usually, the operator at the conference convoker terminal) mediate their opinions among the participators.
In such a prior art conference telephone system that allows mutual conversations between the operators as the conference participator members through their extension telephones, when the number of participator members becomes too large, it becomes difficult for the chairman operator to discriminate the identity of the talkers and thus to mediate their opinions, which results in that the maximum number of participator members is limited to usually about 6.
In actual applications, a telephone conference is often carried out among more than 7 participator members. In such a case, the above prior art conference telephone system has had such a problem that the conference convoker cannot have the initiative in the conference and when all the participator members start talking with each other at a time, it often becomes difficult for him to secure the command of the conference.
In this way the prior art conference telephone system based on the private branch exchange has had many problems which include the following, because the system allows free mutual talks between the operators a the respective extension telephones.
(1) The system tends to easily incur the confusion of speeches. PA0 (2) It becomes difficult for the conference caller to have the initiative of the conference and thus sometimes difficult to hold the command of the conference. PA0 (3) The system is not suitable for such a telephone conference application, in particular, that the number of conference participator members exceeds 6.